Viktor Hartung | Searcharxiv

arXiv2026

First in-vivo human magnetic particle imaging

Magnetic particle imaging (MPI) is a tracer-based technique that directly detects the distribution of magnetic iron-oxide nanoparticles with millisecond temporal resolution and no tissue background. Despite extensive preclinical work, in-vivo application of MPI in humans has not previously been reported. Here, we report the first in-vivo human MPI angiography, visualizing venous perfusion of the upper extremity using a human-scale scanner and clinically approved ferucarbotran. Under identical procedural conditions, we performed X-ray digital subtraction angiography as the clinical gold standard. MPI visualized major superficial and deep veins, including inflow, branching, valve filling, and clearance dynamics in real time with 2 frames per second. These results establish magnetic particle imaging as a clinically translatable modality for radiation-free vascular imaging in humans and mark the transition of MPI from preclinical research to first clinical application.

physics.med-ph↗

arXiv2025

Technical recommendation on multiplex MR elastography for tomographic mapping of abdominal stiffness with a focus on the pancreas and pancreatic ductal adenocarcinoma

Objectives: MR elastography (MRE) offers valuable mechanical tissue characterization, however, in deep abdominal organs like the pancreas conventional single-driver, single-frequency approaches often fail. This study evaluates whether multiplex MRE using multiple drivers and vibration frequencies can overcome these limitations. Methods: This study used single-shot spin-echo MRE in 18 healthy volunteers targeting the liver, pancreas, kidneys, and spleen. Each healthy volunteer underwent 16 MRE examinations with different sets of four vibration frequencies (30-60 Hz) and four driver combinations, and an additional null experiment without vibrations. Further, a cohort of 14 patients with pancreatic ductal adenocarcinoma (PDAC) were retrospectively assessed. The quality of shear-wave fields and stiffness maps was assessed by displacement amplitudes and image sharpness. Results: In healthy volunteers, abdominal coverage with displacement amplitudes above the pre-determined noise level of 4 {\mu}m varied between MRE configurations: 24.2% ([0.0%-56.2%], single-driver, 60 Hz), 66.9% ([24.8%-97.7%], single-driver, 30-60 Hz), 70.2% ([0.0%-92.5%], multi-driver, 60 Hz) and 99.9% ([89.4%-100%], multi-driver, 30-60 Hz). In the pancreas, >60% coverage was achieved in all subjects using four drivers and multiple frequencies. This was achieved in only 2/18 subjects using single-driver/single-frequency MRE. Patients with PDAC had 99.1% [91.4%-100%] coverage in the pancreas and 96.3% [63.1%-100%] abdominal coverage (multi-driver, 30-60 Hz). Conclusion: MRE with four drivers and multiple vibration frequencies between 30-60 Hz enables tomographic mapping of tissue stiffness across the entire abdomen, including the pancreas. Multiplex MRE offers a promising approach for generating detailed images of abdominal stiffness, potentially enhancing clinical diagnostics for abdominal and pancreatic diseases.

physics.med-ph↗